umbraco-nested-sitemap.cshtml

@inherits Umbraco.Web.Mvc.UmbracoTemplatePage
@{
  var homePage = Model.Content.Site();
}

@helper RenderChildPages(IEnumerable<IPublishedContent> pages)
{
  if (pages.Any())
  {
    <ul>
      @foreach (var page in pages.Where("Visible"))
      {
        if (!(page.HasProperty("excludeFromSitemap") && (bool)page.GetPropertyValue("excludeFromSitemap")))
        {
          <li>
            <a href="@page.Url">@page.Name</a>
            @{
              var childPages = page.Children.Where("Visible");
              @RenderChildPages(childPages)
            }
          </li>
        }
      }
    </ul>
  }
}

<nav class="sitemap-nav">
  <ul>
    @if (homePage.Children.Where("Visible").Any())
    {
      var childPages = homePage.Children.Where("Visible");

      <ul>
        <li class="home">
          <a href="/">@homePage.Name</a>
          @RenderChildPages(childPages)
        </li>
      </ul>
    }
  </ul>
</nav>